enic: Bug Fix: Fix hardware descriptor reads

The last bit written to a completion descriptor by hardware is the color
bit. Driver must read all other descriptor fields only after reading the
color bit to avoid reading stale descriptor fields.  There is a rmb() after
reading the color bit to avoid any compiler/cpu reordering of the reads.
The color bit is the generation bit that toggles each pass through the
completion descriptor ring.

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vasanthy Kolluri 2010-03-18 16:19:44 +00:00 committed by David S. Miller
parent ba7e94a44a
commit a55a603dae
2 changed files with 9 additions and 5 deletions

View File

@ -101,14 +101,18 @@ static inline void cq_enet_rq_desc_dec(struct cq_enet_rq_desc *desc,
u8 *tcp_udp_csum_ok, u8 *udp, u8 *tcp, u8 *ipv4_csum_ok, u8 *tcp_udp_csum_ok, u8 *udp, u8 *tcp, u8 *ipv4_csum_ok,
u8 *ipv6, u8 *ipv4, u8 *ipv4_fragment, u8 *fcs_ok) u8 *ipv6, u8 *ipv4, u8 *ipv4_fragment, u8 *fcs_ok)
{ {
u16 completed_index_flags = le16_to_cpu(desc->completed_index_flags); u16 completed_index_flags;
u16 q_number_rss_type_flags = u16 q_number_rss_type_flags;
le16_to_cpu(desc->q_number_rss_type_flags); u16 bytes_written_flags;
u16 bytes_written_flags = le16_to_cpu(desc->bytes_written_flags);
cq_desc_dec((struct cq_desc *)desc, type, cq_desc_dec((struct cq_desc *)desc, type,
color, q_number, completed_index); color, q_number, completed_index);
completed_index_flags = le16_to_cpu(desc->completed_index_flags);
q_number_rss_type_flags =
le16_to_cpu(desc->q_number_rss_type_flags);
bytes_written_flags = le16_to_cpu(desc->bytes_written_flags);
*ingress_port = (completed_index_flags & *ingress_port = (completed_index_flags &
CQ_ENET_RQ_DESC_FLAGS_INGRESS_PORT) ? 1 : 0; CQ_ENET_RQ_DESC_FLAGS_INGRESS_PORT) ? 1 : 0;
*fcoe = (completed_index_flags & CQ_ENET_RQ_DESC_FLAGS_FCOE) ? *fcoe = (completed_index_flags & CQ_ENET_RQ_DESC_FLAGS_FCOE) ?

View File

@ -34,7 +34,7 @@
#define DRV_NAME "enic" #define DRV_NAME "enic"
#define DRV_DESCRIPTION "Cisco 10G Ethernet Driver" #define DRV_DESCRIPTION "Cisco 10G Ethernet Driver"
#define DRV_VERSION "1.1.0.241a" #define DRV_VERSION "1.3.1.1"
#define DRV_COPYRIGHT "Copyright 2008-2009 Cisco Systems, Inc" #define DRV_COPYRIGHT "Copyright 2008-2009 Cisco Systems, Inc"
#define PFX DRV_NAME ": " #define PFX DRV_NAME ": "